Agitating ejector type dental lathe pan



u 3, 1947- R. L. GUEDEL 2,421,498

AGITATI NG EJECTOR TYPE DENTAL LATHE PAN Filed May 8, 194a IN V EN TOR.

- Maw ATTOBNEi? Patented June 3, 1947 UNITED STATES PATENT OFFICE AGITATING EJECTOR" TYPE DENTAL LATHE PAN Robert Louis Guedel, Indianapolis, Ind.

Application May 8, 1946, Serial No. 668,266

15 Claims. 11

The present invention relates to an agitator ejector type dental lathe pan, and is particularly concerned with means for providing a continuous stream. of abradent slurry torun or drip upon a dental stone or burr being used for grinding or polishing of any article. While the device has been designed primarily for use by dentists and dental technicians, it will be clear, as the following disclosure is considered, that the device is equally applicable in connection with any polishing operation where it isdesirable that an abradent suspension shall be continuously supplied under substantially uniform conditions of abradent concentration.

In such polishing and grinding operation, powdered pumice, suspended in any suitable liquid, for instance, water, should be continuously supplied to the surface being actedupon by a rotating stone, burr, or polishing wheel. The suspension is a relatively thick slurry; and if it is allowed to lie quiescent for any material length of time, it is likely to dry and become hard. Unless the supply of slurry is continuously agitated, throughout its mass, various portions of the mass will acquire varying concentrations or thicknesses; and of course such a condition is undesirable.

Among the objects, then, of the present invention are to provide a simple and inexpensive mechanism which will continuously agitate a storage supply of such slurry and which will continuously elevate and discharge, from a suitable spout or trough, a stream of abrad'en-t slurry of uniform consistency; to provide such a device which will agitation to maintain uniformity throughout the storage mass; to provide a, very simple pump for circulating the mass; to provide, in such a device, structure capable of ready disassembly for cleaning; to provide means, embodied in the device, for preventing the slurry from being thrown, by the polishing wheel, out of the assembly; to provide unusual facility for draining and cleaning the entire assembly; and to provide structural means effecting considerable flexibility in. the location of the point of discharge of the flowin stream of slurry. Further objects of the invention will appear as the description proceeds.

To the accomplishment of the above and related objects, my invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings arev illustrative only, and that accomplish an unusually effective change may be made in the specific construction 55 2 illustrated and described, so long as the scope of the appended claims is not. violated.

Fig. l is a transverse section through an as.- semhly embodying my invention;

Fig. 2 is a front elevation thereof; and

Fig. 3: is an inverted perspective view of an agitator unit. formin an element of my invention.

Referring more particularly to the drawings, itwillf be seen that I have. illustrated a vat; indicatedgenerallyby the reference numeral Ill, and preferably, though not: necessarily, so formed that the upper extremity ll of its rear wall is located in a horizontal plane somewhat higher than that occupied by the uper edge [2 of its front wall. Preferably, the vat is supported upon a plurality of standards. I13, 13:, elevating the bottom wall I14. of said vat above the surface'of a table, bench, or' the like, 15 to which the. standards l3 may, if desired, be secured by screws, bolts, or any equivalent fastening means.

bottom wall [4 of the vat ill is provided with an. opening it inv which is received a journal bearing ll which, in the illustrated embodiment of the invention is. shown to. be. provided. with a sealing collar it through which the bearing is secured in place by screws I 9, or the. like. A shaft, indicatedv generally by the reference numeral 20, is vertically journalled in said bearing II. In the illustrated embodiment of the invention, said shaftcom-prisesa lower section 2| having a polygonal upper end 22 which is received in a correspondingly formed socket in the lower end of an upper shaft section 273, formed as an Archimedes An agitator, indicated generally by the reference numeral 2'4, is, in the illustrated embodiment of the invention, clamped in place between the upper and lower secti-onsof the shaft 20.

Surrounding the shaft section 23 is a tubular casing 25, supported and secured in place by means of a clamping bracket 26' carried upon the rear wall of the vat l, and cooperating with said shaft section 2.3 to form a liquid pump. Near its lower end, the casing 25 is formed with an inlet port 21 and near its upper end, said casing is formed with an axially elongated outlet port 28.

For a reasonwhich will later appear, the upper end of shaft section 231s formed with a polygonal head 29. v

The agitator 24 comprises a plate 30 having an upwardly and outwardly inclined perimetral flange 3 1, so that said agitator may be considered to be a pan. Radiating from the center of the plate 30' are a plurality of series of perforations 32a, 32b, 32c, and 32d, the number of said series and the number of perforations in each series being a, matter of choice. Associated with each series of perforations is a shield or scoop, indicated generally by the reference numerals la, 51b, 51c, and 51d, each of such scoops being secured to the plate rotationally immediately behind its associated series of perforations, and inclined downwardly and rotationally forwardly to overlap its associated series of perforations. It will be clear that this arrangement will cause slurry in the vat IE] to be scooped up by the said scoops, as the agitator rotates, and to be forced thereby, through the associated pan perforations. Thus, the slurry will build up in the pan and finally overflow the edge of the flange 3 I, whence it tends to fall again to the bottom of the vat.

A sheave 33 is suitably secured to the bottom end of the shaft section 2| below the bottom of the vat l4, and is adapted to be driven, through a belt 34, from a sheave 35 secured to the spindle 36 of a motor 31 which may preferably be hung, by bolts 38 or the like, from the back wall of the vat I0.

A sleeve 39 is telescopically received upon the upper end of the casing 2'5, and is adjustable thereon to vary the position of the outlet trough 43, both vertically with respect to the vat l0, and rotationally with respect to the axis of the casing 25. The trough or spout 40 communicates with the interior of the casing 25 and inclines radially outwardly from said axis, and downwardly from the upper end of the sleeve 39; and preferably an auxiliary spout section 4| is telescopically and slidably associated therewith in order to vary the position of the discharge stream, radially with respect to the axis of the casing 25.

A hood 42 is hingedly associated with the vat I0, as at 43, and is swingable between the position illustrated in solid lines, in which it confines abradent material thrown from the grinding or polishin wheel, and the position illustrated in dotted lines, in which it is out of the way to permit access to the pump and agitator parts.

Near the bottom of the front wall of the vat, I provide a cleanout and drain port 44, normally closed by a threaded plug 45 provided, at its outer end, with a polygonal head 46 correspondin 'in contour to the shaft section head 29, and provided at its inner end with a sealing flange 41 adapted to seat upon the inner surface of said vat wall about the port 44. Preferably, I provide a drain trough 48 adapted to be positioned adjacent said port 44. Conveniently, said trough will be formed with a tongue 49 receivable between the bottom wall I4 of the vat and the transverse stretcher of the front pedestal element l3, said vat bottom being conveniently spaced from said stretcher by washers 50, 50.

The operation of the disclosed device will be clear. When the motor 31 is energized, the shaft '20 will be rotated. Assuming a level of slurry in the vat at least as high as the forwardly-directed edges of the scoops 5la, etc., slurry will be forced upwardly through the perforations 32a, etc, and will overflow the flange 3| of the agitator 24, whereby the slurry will be kept constantly of uniform consistency. The abradent suspension will enter the casing 25 through port 27, and will be carried upwardly through said casing by the screw 23, thence to be discharged through the port 28 and the trough 40, 4|. The stream will fall upon the work or the grinding or polishing wheel, and thence will return to the vat Hi.

It may sometimes happen that, after a relatively long period of non use, the abradent material may harden and cake inside the casing 25, thus providing such a resistance to rotation of the screw 23 as to prevent starting thereof by the motor 31. Under such circumstances, the hood 42 may be moved to its dotted line position, and the sleeve 39 may be shifted downwardly to expose the polygonal shaft end 29. A wrench may then be engaged with said shaft end, and such force may be manually applied to the shaft as may be necessary to break it loose, after which, the motor will be capable of continuing operation of the mechanism.

Preferably, the heads 29 and 46 will conform in contour, so that a single wrench may be used to engage either head.

For ordinary cleaning, it will be noted that the screw 23 may be freely lifted from the upper end of the housing 25, without preliminary loosening. The casing 25 may be removed from the assembly merely by releasing the clamp 26. After removal of the screw 23 and casing 25, the agitator 24 may be freely lifted out of the assembly. If it becomes necessary to remove the shaft section 2! or the bearing I! for cleaning or replacement, it is merely necessary to remove the sheave 33 from the shaft section and thereafter to remove the screws [9.

The present application is a continuation in part of my copending application, Serial Number 627,908, filed November 10, 1945, for Agitating ejector type dental lathe pan.

I claim as my invention:

1. In a device of the class described, a vat for containing an abradent slurry, a screw shaft vertically journalled in said vat and carrying near the bottom of said vat, an agitator, and a casing surrounding said screw shaft and cooperating therewith to form a liquid pump, said casing being formed, near the bottom of said vat, with an inlet port, and near the top of said casing with an outlet port.

2. The device of claim 1 in which said agitator is in the form of a perforated plate substantially parallel with the bottom of said vat.

3. The device of claim 1 in which said agitator is in the form of a plate substantially parallel with the bottom of said vat and formed with a plurality of perforations therethrough, and in which said plate carries, on one surface, a plurality of scoops, each scoop being secured to said plate adjacent a series of said perforations and inclining away from said plate and in the direction of rotation of said plate.

4. The device of claim 1 in which said agitator is in the form of a plate substantially parallel with the bottom of said vat and formed with a plurality of perforations therethrough, and in which said plate carries, on its lower surface, a plurality of scoops, each scoop being secured to said plate adjacent a series of said perforations and inclining downwardly and in the direction of rotation of said plate.

5. The device of claim 1 in which said agitator is in the form of a pan, generally parallel to the bottom of said vat, formed with a plurality of perforations therethrough, and having an upwardly and outwardly inclined perimetral flange, and in which said agitator carries, on its lower surface, a plurality of scoops, each scoop being secured to said agitator adjacent a series of said perforations and inclining toward the bottom of said vat and in the direction of rotation of said agitator.

6. The device of claim 1 in which said agitator is in the form of a plate substantially parallel with the bottom of said vat and formed With a plurality of series of perforations therethrough each of said series being arranged on a radial line emanating from the axis of rotation of said screw, and in which said plate carries, on one surface, a plurality of scoops, each scoop being secured to said plate on a radial line emanating from said axis and rotationally rearwardly adjacent a series of perforations, and inclining away from said plate and in the direction of rotation of said plate to overlap its associated series of perforations.

7. In a device of the class described, a vat containing an abradent slurry, a screw shaft vertically journalled in said vat, an agitator mounted for rotation near the bottom of said vat, a casing surrounding said screw shaft and cooperating therewith to form a liquid pump, said casing being formed, near the bottom of said vat, with a lateral inlet port, and near the top of said casing with an elongated outlet port, and a sleeve telescopically and adjustably mounted on said casing near the top thereof and operable to mask a selected portion of said casing outlet port.

8. In a device of the class described, a vat for containing an abradant slurry, a screw shaft vertically journalled in said vat, an agitator mounted for rotation near the bottom of said vat, a casing surrounding said screw shaft and cooperating therewith to form a liquid pump, said casing being formed, near the bottom of said vat, with a lateral inlet port, and near the top of said casing with an elongated outlet port, a sleeve telescopically and adjustably mounted on said casing near the top thereof and operable to mask a. selected portion of said casing outlet port, and a laterally-projecting outlet spout carried by said sleeve.

9. In a device of the class described, a vat for containing an abradent slurry, a screw shaft vertically journalled. in said vat, an agitator mounted for rotation near the bottom of said vat, a casing surrounding said screw shaft and cooperating therewith to form a liquid pump, said casing being formed, near the bottom of said vat, with a lateral inlet port, and near the topof said casing with an elongated outlet port, a sleeve telescopically and adjustbly mounted on said casing near the top thereof and operable to mask a selected portion of said casing outlet port, a laterally-projecting outlet spout carried by said sleeve, and means for varying the effective length of said spout.

10. In a device of the class described, a vat for containing an abradent slurry, one edge portion of said vat being higher than the opposite edge portion thereof, a screw shaft vertically journalled in said vat, an agitator mounted for rotation near the bottom of said vat, a casing surrounding said screw shaft and cooperating therewith to form a liquid pump, said casing being formed, near the bottom of said vat, with 2, lateral inlet port, and. near the top of said casing with an outlet port opening toward said opposite vat edge portion, and a hood hingedly mounted upon said one edge and swingable into and out 6 of a piston overlying said casing outlet port.

11. The device of claim 1 in which the top of said casing is open, and in which said screw shaft is provided with a polygonal upper end accessible for manual manipulation through the top of said casing.

12. The device of claim 1 in which said vat is provided with a cleanout port, and in which a threaded plug for said port is provided with a polygonal outer end accessible from outside said vat, and with an enlarged inner end adapted to seal against the inner surface of said vat about said cleanout port.

18. The device of claim 1 in which the top of said casing is open, in which said screw shaft is provided with a polygonal upper end accessible for manual manipulation through the top of said casing, in which said vat is provided with a cleanout port, and in which a threaded plug for said port is provided with a polygonal outer end conforming to the upper end of said shaft and accessible from outside said vat, and with an enlarged inner end adapted to seal against the inner surface of said vat about said cleanout port.

14. In a device of the class described, a vat for containing an abradent slurry, spaced means for supporting said vat with its bottom spaced above a supporting surface, the bottom of said vat being formed with an opening therethrough, bearing means penetrating said opening, means removably securing said bearing means in place, a screw shaft vertically journalled in said bearing means and projecting upwardly therefrom, an agitator carried on said screw shaft within said vat and near the bottom thereof, a casing surrounding said screw shaft and cooperating therewith to form a liquid pump, said-casing being-formed, near the bottom of said vat, with an inlet port, and near the top of said casing with an outlet port, and a rotary-driving-power receiving element fixed to said screw shaft beneath the bottom of said vat.

15. In a device of the class described, a vat for containing an abradent slurry, spaced means for supporting said vat with its bottom spaced above a supporting surface, the bottom of said vat being formed with an opening therethrough, bearing means penetrating said opening, means removably securing said bearing means in place, a screw shaft vertically journalled in said bearing means and projecting upwardly therefrom, an agitator carried on said screw shaft within said vat and near the bottom thereof, a casing surrounding said screw shaft and cooperating therewith to form a liquid pump, said casing being formed, near the bottom of said vat, with an inlet port, and near the top of said casing with an outlet port, a rotary-driving-power receiving element fixed to said screw shaft beneath the bottom of said vat, a motor removably secured to an external wall of said vat and having a spindle extending into a plane below the bottom of said vat, and a member in said spindle drivingly associated with said element on said screw shaft.

ROBERT LOUIS GUEDEL.

Certificate of Correction Patent No. 2,421,498. June 3, 1947. ROBERT LOUIS GUEDEL It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Column 6, line 1, for the word piston read position; and that the said Letters Patent should be read with this gorrection therein that the same may conform to the record of the case in the Patent fiice.

Signed and sealed this 15th day of July, A. D. 1947.

LESLIE FRAZER,

First Assistant Gammz'ssz'oner of Patents. 

